A Babcock bottle is a clear glass flask with a long graduated neck, used in the Babcock test to evaluate the cream contents of milk. [1] It is also called a Babcock milk test bottle, milk test bottle, cream test bottle, and other similar names. [2] [3] [4] [5]
This bottle (or variations thereof) may also be used to estimate the amount of a lighter phase in other two-phase mixtures, such as are obtained in standard tests for gasoline and other petroleum products. [6] [7] [5] [8] [9]
The Babcock test consists in adding to a standard sample of the milk certain chemicals that cause the fat to separate into a liquid layer, floating at the top of a water-based layer. More water is then added to the mixture, until the fat layer is completely inside the neck, where its volume can be read out from the scale. [10]
The Babcock bottle for milk testing was standardized with great detail in 1917 by the American Dairy Science Association (ADSA). The total height should be 150-165 mm, and the neck should be at least 63.5 mm long. The body should have a capacity of at least 45 mL. The graduated scale on the neck should have marks at every 0.02 mL of internal volume, corresponding to 0.1 percent fat in a standard sample of 17.6 mL (18 grams) of milk, from 0 to 8 percent. The top must be flared to at least 10 mm diameter. [10] [5]
The bottle usually has a bullet-shaped body for easy cleaning. Its width and shape were chosen to match the manual centrifuges originally used in the Babcock test. The body was 37 mm wide just below the rounded top, and might be cylindrical or slightly tapered inwards going down. The minimum capacity of 45 mL is intended to contain the standard sample of milk, and at least an equal amount of other reagents. Some bottles had a ground glass stopper. [11]
Babcock bottles for measuring the fat contents in cream have wider necks to allow for readings of 50% or more (rather than up to 8%). [12]
Louis Nafis patented in 1921 a modified Babcock bottle, claimed to be less susceptible to accidental breakage. Instead of the integral long graduated neck, it had a short neck to which a rubber ring was fitted. After processing and centrifuging the milk in the bottom part, two other glass parts would be added. A wider glass tube would be hermetically fitted on the outer edge of that ring, and inside it would be placed a narrow graduated tube, with a flared opening at bottom, resting on the rubber ring without a seal. Warm water would be poured down between the two tubes, seep under the inner tube, and lift the fat into the latter. [13] However, there seems to be no evidence that this invention has ever been marketed or used.
A variant of the Babcock bottle has a glass tube parallel to the neck, that crosses the wall of the body and ends just above its bottom. It allows the addition of water without disturbing the layer of fat as it rises into the graduated neck. In this variant, the flaring is on the auxiliary tube instead of on the neck. [14]
Another variant of this flask is the Paley-Babcock or Paley bottle, which is intended for viscous liquids or solids (like cheese or meat) that would be difficult to introduce through the narrow neck. It has an opening on the body, just below the neck, that can be closed with a stopper. [15] [16] [17]
A Babcock bottle with different dimensions (165 mm high, 10 mL capacity) is used to determine the amount of unsaturated hydrocarbons in gasoline. [18] [7]
The Babcock bottle was originally developed to determine the fat content of milk. [3] [4] Other uses of the container and its variations include measuring the contents of:
The bottle and the test were developed in 1890 by Stephen M. Babcock (1843–1931), professor at the University of Wisconsin, [28] [29]
In 1911, ADSA's Committee on Official Methods of Testing Milk and Cream for Butterfat, chaired by O. F. Hunziker, met in Washington DC with the Dairy Division of the USDA, the U.S. Bureau of Standards and manufacturers of glassware. [4] As a result of those talks, the procedure and glassware were standardized by the US Government in 1917. [10] [30] Additional specifications were published by the Association of Official Agricultural Chemists (now AOAC International) in 1927. [31]
An earlier manufacturer of Babcock bottles was Louis F. Nafis (1874–1955), [32] whose eponymic Chicago-based company was sold to the Kimble Glass Company (now part of DWK Life Sciences) in 1932. [33] [1]
Milk is a white liquid food produced by the mammary glands of mammals. It is the primary source of nutrition for young mammals before they are able to digest solid food. Immune factors and immune-modulating components in milk contribute to milk immunity. Early-lactation milk, which is called colostrum, contains antibodies that strengthen the immune system, and thus reduces the risk of many diseases. Milk contains many nutrients, including protein and lactose.
Butter is a dairy product made from the fat and protein components of churned cream. It is a semi-solid emulsion at room temperature, consisting of approximately 80% butterfat. It is used at room temperature as a spread, melted as a condiment, and used as a fat in baking, sauce-making, pan frying, and other cooking procedures.
Casein is a family of related phosphoproteins that are commonly found in mammalian milk, comprising about 80% of the proteins in cow's milk and between 20% and 60% of the proteins in human milk. Sheep and buffalo milk have a higher casein content than other types of milk with human milk having a particularly low casein content.
Buttermilk is a fermented dairy drink. Traditionally, it was the liquid left behind after churning butter out of cultured cream. As most modern butter in western countries is not made with cultured cream but uncultured sweet cream, most modern buttermilk in western countries is cultured separately. It is common in warm climates where unrefrigerated milk sours quickly.
Decantation is a process for the separation of mixtures of immiscible liquids or of a liquid and a solid mixture such as a suspension. The layer closer to the top of the container—the less dense of the two liquids, or the liquid from which the precipitate or sediment has settled out—is poured off, leaving the other component or the denser liquid of the mixture behind. An incomplete separation is witnessed during the separation of two immiscible liquids. To put it in a simple way, decantation is separating immiscible materials by transferring the top layer to another container. The process does not provide accurate or pure product.
Blue cheese is semi-soft cheese with a sharp, salty flavor. It is made with cultures of the edible mold Penicillium, giving it spots or veins throughout the cheese in shades of blue or green. It carries a distinct smell, either from the mold or from various specially cultivated bacteria such as Brevibacterium linens, which also causes foot odor and other human body odors.
Dairy cattle are cattle bred for the ability to produce large quantities of milk, from which dairy products are made. Dairy cattle generally are of the species Bos taurus.
The Babcock test is an inexpensive and practical procedure to determine the fat content of milk. It is named after its developer, Stephen M. Babcock (1843–1931), professor at the University of Wisconsin.
The American Dairy Science Association (ADSA) is a non-profit professional organization for the advancement of dairy science. ADSA is headquartered in Champaign, Illinois.
Chewiness is the mouthfeel sensation of labored chewing due to sustained, elastic resistance from the food. Foods typically considered chewy include caramel, rare steak, and chewing gum. Other foods where this is an important part of the experience of eating include springy cheeses and apples.
Granular cheese, also known as stirred curd cheese and hard cheese, is a type of cheese produced by repeatedly stirring and draining a mixture of curd and whey. It can refer to a wide variety of cheeses, including the grana cheeses such as Parmigiano-Reggiano (pictured) and various others. Many types are commonly used in the production of processed cheese, especially American cheese, which by law must consist of Cheddar cheese, Colby cheese, cheese curd, or granular cheese.
Κ-casein, or kappa casein, is a mammalian milk protein involved in several important physiological processes. Chymosin splits K-casein into an insoluble peptide and water-soluble glycomacropeptide (GMP). GMP is responsible for an increased efficiency of digestion, prevention of neonate hypersensitivity to ingested proteins, and inhibition of gastric pathogens. The human gene for κ-casein is CSN3.
Otto Frederick Hunziker was a pioneer in the American and international dairy industry, as both an educator and a technical innovator. Hunziker was born and raised in Switzerland, emigrated to the U.S., and studied at Cornell University. He started and developed the dairy program at Purdue University when such programs were at their infancy. At this same time, Hunziker was heavily involved with the development of the American Dairy Science Association (ADSA) and the standardization and improvement of many dairy tests and processes. Hunziker wrote several of the leading dairy processing texts, which continue to be cited. After leaving Purdue University, Hunziker managed research and operations at a large, national condensary, continued to drive ADSA's standardization and publishing efforts, represented the U.S. at international dairy congresses, and facilitated dairy industry improvements across the globe.
The fat content of milk is the proportion of milk, by weight, made up by butterfat. The fat content, particularly of cow's milk, is modified to make a variety of products. The fat content of milk is usually stated on the container, and the color of the label or milk bottle top varied to enable quick recognition.
Charles Roy Henderson was an American statistician and a pioneer in animal breeding — the application of quantitative methods for the genetic evaluation of domestic livestock. This is critically important because it allows farmers and geneticists to predict whether a crop or animal will have a desired trait, and to what extent the trait will be expressed. He developed mixed model equations to obtain best linear unbiased predictions of breeding values and, in general, any random effect. He invented three methods for the estimation of variance components in unbalanced settings of mixed models, and invented a method for constructing the inverse of Wright's numerator relationship matrix based on a simple list of pedigree information. He, with his Ph.D. student Shayle R. Searle, greatly extended the use of matrix notation in statistics. His methods are widely used by the domestic livestock industry throughout the world and are a cornerstone of linear model theory.
The Gerber method is a primary and historic chemical test to determine the fat content of substances, most commonly milk and cream. The Gerber method is the primary testing method in Europe and much of the world. The fairly similar Babcock test is used primarily in the United States, although the Gerber method also enjoys significant use in the U.S. as well.
The Latxa is a breed of domestic sheep native to the Basque Country of Spain. Mostly contained within the provinces of Biscay, Gipuzkoa and Navarre, Latxa are dairy sheep whose unpasteurized milk is used to produce Idiazábal and Roncal cheeses. There are two sub-types of the breed, a dark-faced and a blonde.
Thermization, also spelled thermisation, is a method of sanitizing raw milk with low heat. "Thermization is a generic description of a range of subpasteurization heat treatments that markedly reduce the number of spoilage bacteria in milk with minimal heat damage." The process is not used on other food products, and is similar to pasteurization but uses lower temperatures, allowing the milk product to retain more of its original taste. In Europe, there is a distinction between cheeses made of thermized milk and raw-milk cheeses. However, the United States' Food and Drug Administration (FDA) places the same regulations on all unpasteurized cheeses. As a result, cheeses from thermized milk must be aged for 60 days or more before being sold in the United States, the same restriction placed on raw-milk cheeses by the FDA.
Lore Alford Rogers was an American bacteriologist and dairy scientist. He is credited with discovering that butter made from pasteurized sweet cream remained fresher than that made from sour ripened cream, while suggesting that surplus milk could still be sold as concentrated sour milk products. He refined the steps for manufacture of high quality Swiss cheese and, new to the United States, production of Roquefort cheese. He was instrumental in finding ways to discourage fungal growth in sweetened condensed milk and preventing losses in evaporated milk from heat coagulation.
Louis Firth Nafis was an American entrepreneur and inventor, best known as the first manufacturer of the standard Babcock milk test bottle. He was born in Jersey City, New Jersey on November 1, 1884, and died on February 26, 1955, in Evanston, Illinois.